Abstract : This paper utilizes the memory characteristic of RS flip-flops to suppress contact interference in switches. Keywords : Electrical contact pressure gauge; RS flip-flop; contact interference. The electrical contact pressure gauge differs from a conventional pressure gauge in that it has two electrical contacts. The middle movable contact can swing with the gauge pointer, while the other two contacts can be arbitrarily set to control the pressure range. In other words, the electrical contact pressure gauge is not only an indicating device but also a control device, commonly used to adjust the pressure of a system. The general usage of an electrical contact pressure gauge is to directly control the coil of an intermediate relay using the two contacts of the gauge, as shown in Figure 1. In Figure 1, SY1 is the low-pressure contact of the pressure gauge, and SY2 is the high-pressure contact. When the system pressure drops to the low set point, SY1 closes. Pressing the self-holding switch K energizes and closes Ji, starting the water pump motor. When the system pressure reaches the high set point, SY2 closes, the normally closed contact of J2 opens, Ji is de-energized, and the water pump stops working. When the system pressure returns to the low set point, SY1 closes, and the cycle repeats. Thus, contact bounce causes several problems in practical applications. First, contact erosion occurs. Each time the contacts close and open, they bounce several times, generating sparks under high voltage. After a period of time, the contacts become blackened and oxidized, leading to poor contact. Secondly, and more importantly, contact bounce generates severe interference, preventing other circuits (low-voltage control circuits) from functioning properly. Considering these reasons, and taking into account the self-memory function of RS triggers, the interference caused by pressure gauge contact bounce can be suppressed. [b][align=center]For more details, please click on the application of RS triggers in industrial control[/align][/b]